In its simplest and earliest form, an instrument for catheterization was a tubular object used to drain noxious material (e.g. pus) from the body. The instrument had a proximal end, generally sharp, to allow penetration of tissue or of a body structure, a tubular shaft with a lumen, and an open distal end to allow drainage and introduction of other substances and devices. This instrument has evolved to a plethora of devices (e.g. needles, catheters of different types, cannulae, and biopsy tools, etc.) for catheterization of structures. Each of these has its own specific use(s), method of insertion, problems and complications.
Catheterization of a blood vessel will be used as an illustration. Catheters for blood vessels were initially developed for insertion into peripheral vessels, those which the practitioner could see and/or feel, e.g. on the dorsum of the hand or along the arm. With advances in medicine, it became necessary to catheterize larger blood vessels, many of which were neither visible nor palpable. This required a change in the procedure of catheterization. Several special-purpose catheters and insertion kits (described hereinafter) have become available for the diagnosis and treatment of medical problems. However, problems still exist during and after catheterization. It is one object of this invention to correct these problems.
There is no catheterization system available which is universal, i.e.:
has a universal procedural method;
can be used to catheterize almost all structures, regardless of the site in/on the body;
can be used both endoscopically and on the surface of the body;
can be used for diagnosis and treatment in all parts of the body using the same procedure.
It is a further object of this invention to be comprehensive, efficient and to fill this void.
This invention rectifies old problems and eliminates some of the newer ones (e.g. risk of AIDS by transmission of the HIV virus from patient to practitioner or vice-versa). Moreover, the invention described here is a universal system. It is also a discriminatory system because it allows a system of treatment that is less toxic to the patient, hence more humane. This system requires fewer hospitalizations and is therefore less expensive. It is more efficient in diagnosis and allows appropriate therapy to be initiated during the same procedure. ILLUSTRATION:
At present, catheterization of the subclavian vein requires the following steps:
1) The skin is cleansed with the solution of choice.
2) The anaesthetic is locally infiltrated.
3) The anatomic landmarks are identified again.
4) The vessel is blindly punctured using a needle with attached syringe.
5) "Flash-back" of blood is observed in the syringe.
6) The syringe is detached from needle so that a guide-wire can be introduced through the hub of the needle.
7) The needle is withdrawn, leaving the guide-wire in place.
8) An incision made in skin at the site of the guide-wire in the skin.
9) A dilator is introduced over the guide-wire through skin into the blood vessel. This makes a passage in the tissues so that the catheter can subsequently be introduced with ease.
10) The dilator is threaded back out over the guide-wire.
11) The catheter is threaded over the guide-wire into the blood vessel.
12) The guide-wire is removed, leaving catheter in place.
13) The infusion lines are attached to the ports of the catheter.
14) The catheter secured to the skin.;
15) Dressing is applied. (Dressing changes are done under sterile conditions every 2-3 days depending on the protocol.)